code: def test_flip_normal():
      np_points = np.array(
          [[1, 2, 3], [4, 5, 6], [7, 8, 9]], dtype=float
      )
      pset = pv.PointSet(np_points)
      pset.flip_normal([1.0, 1.0, 1.0], inplace=True)
      assert np.allclose(
          pset.points,
          np.array(
              [
                  [7.0, 8.0, 9.0],
                  [4.0, 5.0, 6.0],
                  [1.0, 2.0, 3.0],
              ],
          ),
      )
  
imports: import numpy
  import pytest
  import vtk
  import pyvista
  from pyvista.core.errors import PointSetCellOperationError, PointSetDimensionReductionError, PointSetNotSupported
label_desc: Use image node_id 16 for calling a global function with example usage: test_flip_normal() without return types